Safety syringe

ABSTRACT

The invention pertains to safety syringes designed to protect the operator from unintentional needle sticks and prevent fluid leakage after use. When the safety syringe is in operation, a plunger with an attached piston is pushed into the cylindrical bore forcing fluid through the hollow body, the outlet portion, and out of the hollow needle. A needle shield fits slidably over the needle and a portion of the hollow body. The needle shield is a flattened closure means sealed body. The needle shield&#39;s first position permits the needle&#39;s tip to extend outward from the shield through the closure means. When in the second position, the needle shield to extends beyond the needle&#39;s tip preventing any fluid loss. In a second embodiment, the outlet portion of the syringe cavity also passes through the flattened closure means when the needle shield is in the first position.

RELATED APPLICATION

The instant application is a divisional application of U.S. patent application Ser. No. 09/932,797, filed Aug. 20, 2001.

FIELD OF INVENTION

The invention pertains to medical devices and more particularly to syringes and catheters designed to protect patients and health care workers from unintentional needle sticks and to prevent leakage of fluid from the device after use.

BACKGROUND OF THE INVENTION

In the wake of the HIV epidemic, new and more virulent strains of hepatitis and other blood related diseases, health care workers have become increasingly aware of the potential for deadly consequences related to accidental or unintentional needle sticks or other contact with contaminated bodily fluids. As catheters and syringes are used in immense numbers in modem hospitals and other health care facilities, the opportunity for injury and resulting contamination is significant.

Various devices have been invented in an effort to prevent such injuries. U.S. Pat. No. 5,733,264 issued to Flowers in 1998 discloses a syringe equipped with a sliding tubular shield that slides over the exposed needle after use and locks in place., This shield is, however, open on the distal end, thus permitting fluids to leak from the needle and out the end of the shield. U.S. Pat. No. 5,342,309 issued to Hausser in 1994 is similar in design to the Flowers invention, however employing different means for locking the safety shield in the distal position. Like Flowers, it would appear to be nearly impossible to position this shield over the needle with one hand.

U.S. Pat. No. 5,743,887 issued to Brattesani in 1998 provides for a docking base to help protect the health care worker while attaching and removing the needle from the syringe device. This invention fails to provide a means to control leaks from the needle even though it is encased in a movable safety shield. Likewise, the movement of this shield cannot be easily controlled with one hand. U.S. Pat. No. 5,385,555 issued to Hausser in 1995 is directed towards a syringe having a lockable safety shield slidably positionable over the needle after use. This device also requires two hands to operate and makes no provision for containing any fluid that may drip from the needle.

U.S. Pat. No. 5,647,849 issued to Kalin in 1997 discloses a safety syringe having a slidable barrel that can be positioned over the needle to prevent unwanted injuries. The syringe is provided with a removable seal at the end of the barrel. However, once this seal is removed, there is no convenient way of reattaching the seal to the barrel and thus the potential for leakage remains. Of a slightly different nature, U.S. Pat. No. 4,820,282 issued to Hogan in 1987 relates to a sheath for use in removing hypodermic needles from patients and retaining the point of the removed needle in the sheath when the needle and sheath are disposed of so as to protect against accidentally being pricked.

It is an objective of the invention to provide a means to effectively shield the needle of a syringe or catheter after the device is removed from a patient, thereby preventing accidental needle sticks. It is a further objective of the invention to prevent leakage of fluids from the needle of the catheter or syringe after use. It is yet a further objective of the invention that the shielding capability can be operated with the hand that is operating the syringe or removing the catheter. It is still a further objective of the invention that the safety shield is simple and inexpensive to manufacture.

SUMMARY OF THE INVENTION

(1) A safety syringe may be constructed from the following components. A hollow body is provided. The body is of a first predetermined length and has an outer surface, a first end, a second end, cylindrical bore of a first predetermined diameter. Means are provided for gripping the hollow body adjacent the second end. The first end of the hollow body includes an opening of the first predetermined diameter. The second end includes a cavity extending from the cylindrical bore and terminating in an outlet portion. The outlet portion has a first end, a center section and a second end and is fixedly attached at its first end to the cavity. The outlet portion includes an orifice of a second predetermined diameter that extends outwardly from the cavity.

A hollow needle is provided. The needle has a first end and a second end and is fixedly attached at its first end to the second end of the outlet portion such that fluid may travel from the cylindrical bore, through the cavity, through the and through the needle. A plunger is provided. The plunger has a longitudinal shaft longer than the first predetermined length, a first end and a second end, a thumb pad fixedly attached to the first end of the shaft, and a piston. The piston is formed of a resilient material, attached to the second end of the shaft, and is sized and shaped to fit sealably within the cylindrical bore of the hollow body.

A needle shield is provided. The shield has an outer surface, a first end, a second end, and is sized and shaped to fit slidably over the needle and at least a portion of the hollow body of the syringe. Means are provided for securing the needle shield at its first end to the hollow body in a first position. The first position permits the second end of the needle to extend outwardly from the second end of the shield. A second position permits the second end of the needle shield to extend beyond the second end of the needle. Means are provided for moving the needle shield from the first position to the second position using a single hand. Means are provided for containing any fluid leaking from the second end of the needle within the needle shield when the shield is secured to the hollow body in the second position.

The means for securing the needle shield at its first end to the hollow body in first and second positions includes a first surrounding groove. The first groove is located on the outer surface of the hollow body adjacent its second end. A second surrounding groove is provided. The second groove is located on the outer surface of the hollow body adjacent its first end. An engaging finger is provided. The finger is formed of resilient material and has an upper surface, a lower surface, an activating end, an attaching end and a pivot point located between the ends. A securing tooth is provided. The tooth has an upper end and a lower end and is fixedly attached at its upper end to the lower surface of the engaging is finger adjacent the attaching end. The securing tooth is sized, shaped and located to removably engage one of the first and second surrounding grooves on the hollow body.

A mounting post is provided. The post has an upper end, a lower end and is fixedly mounted at its lower end to the outer surface of the needle shield adjacent its first end. The post is fixedly attached at its upper end to the lower surface of the engaging finger at the pivot point such that the resilient material of the engagement finger will bias the securing tooth downwardly to removably engage one of the first and second surrounding grooves. When pressure is applied to the upper surface of the engaging finger adjacent its activating end the securing tooth will pivot upwardly away from one of the first and second securing grooves, permitting the needle shield to move slidably from the first position to the second position. When the securing tooth is positioned over one of the first and second securing grooves and pressure is relieved from the upper surface of the engaging finger the securing tooth will engage one of the grooves, preventing further movement of the needle shield.

(2) In yet another variant, the means for moving the needle shield from the first position to the second position using a single hand further comprises an indentation located on the outer surface of the needle shield adjacent its first end and is sized and shaped to engage a finger pad of a user.

(3) In still another variant of the invention, the needle shield is formed of a resilient material and the means for containing any fluid leaking from the second end of the needle within the needle shield when the shield is secured to the hollow body in the second position includes a flattened closure means formed at the second end of the needle shield. The closure means has a pair of mating lips at the second end permitting the hollow needle and the second end and center section of the outlet portion to pass between them when the needle shield is in the first position. The lips are capable of sealing the second end of the needle shield when the shield is in the second position with the hollow needle and outlet portion withdrawn within the shield.

(4) In a final variant, the needle shield is formed of a resilient material and the means for containing any fluid leaking from the second end of the needle within the needle shield when the shield is secured to the hollow body in the second position includes a flattened closure means formed at the second end of the needle shield. The closure means has a pair of mating lips at the second end permitting the hollow needle to pass between them when the needle shield is in the first position. The lips are capable of sealing the second end of the needle shield when the shield is in the second position with the hollow needle withdrawn within the shield.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of the safety syringe illustrating the needle shield in a first, closed position and in a second, open position;

FIG. 2 is a detailed perspective view of the FIG. 1 embodiment illustrating the means for securing the needle shield;

FIG. 3 is a perspective view of the FIG. 1 embodiment illustrating the means for moving the needle shield from the first position to the second position;

FIG. 4 is a perspective view of a second embodiment of the safety syringe illustrating the needle shield in a first, closed position and in a second, open position; and

FIG. 5 is a perspective view of the FIG. 2 embodiment of the safety syringe illustrating the mating lips of the needle shield in a first, closed position and in a second, open position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(1) As shown in FIG. 1, a safety syringe 10 may be constructed from the following components. A hollow body 14 is provided. The body 14 is of a first predetermined length 18 and has an outer surface 22, a first end 26, a second end 30, cylindrical bore 34 of a first predetermined diameter 38. Means 42 are provided for gripping the hollow body 14 adjacent the second end 30. The first end 26 of the hollow body 14 includes an opening 46 of the first predetermined diameter 50. The second end 30 includes a cavity 54 extending from the cylindrical bore 34 and terminating in an outlet portion 58. The outlet portion 58 has a first end 62, a center section 66 and a second end 70 and is fixedly attached at its first end 62 to the cavity 54. The outlet portion 58 includes an orifice 74 of a second predetermined diameter 78 that extends outward from the cavity 54.

A hollow needle 82 is provided. The needle 82 has a first end 86 and a second end 90 and is fixedly attached at its first end 86 to the second end 70 of the outlet portion 58 such that fluid (not shown) may travel from the cylindrical bore 34, through the cavity 54, through the outlet portion 58 and through the needle 82. A plunger 94 is provided. The plunger 94 has a longitudinal shaft 98 longer than the first predetermined length 18, a first end 102 and a second end (not shown), a thumb pad 110 fixedly attached to the first end 102 of the shaft 98, and a piston (not shown. The piston is formed of a resilient material (not shown), attached to the second end of the shaft 98, and is sized and shaped to fit sealably within the cylindrical bore 34 of the hollow body 14.

A needle shield 122 is provided. The shield 122 has an outer surface 126, a first end 130, a second end 134, and is sized and shaped to fit slidably over the needle 82 and at least a portion of the hollow body 14 of the syringe 10. Means 138 are provided for securing the needle shield 122 at its first end 26 to the hollow body 14 in a first position 142. The first position 142 permits the second end 90 of the needle 82 to extend outwardly from the second end 134 of the shield 122. A second position 146 permits the second end 134 of the needle shield 122 to extend beyond the second end 90 of the needle 82. Means 150 are provided for moving the needle shield 122 from the first position 142 to the second position 146 using a single hand (not shown). Means 158 are provided for containing any fluid leaking (not shown) from the second end 90 of the needle 82 within the needle shield 122 when the shield 122 is secured to the hollow body 14 in the second position 146.

As shown in FIG. 2, the means 170 for securing the needle shield 122 at its first end 130 to the hollow body 14 in first 142 and second positions 146 further includes a first surrounding groove 174. The first groove 174 is located on the outer surface 22 of the hollow body 14 adjacent its second end 30. A second surrounding groove 178 is provided. The second groove 178 is located on the outer surface 22 of the hollow body 14 adjacent its first end 26. An engaging finger 182 is provided. The finger 182 is formed of resilient material 186 and has an upper surface 190, a lower surface 194, an activating end 198, an attaching end 202 and a pivot point 206 located between the ends. A securing tooth 210 is provided. The tooth 210 has an upper end 214 and a lower end 218 and is fixedly attached at its upper end 214 to the lower surface 194 of the engaging finger 182 adjacent the attaching end 202. The securing tooth 210 is sized, shaped and located to removably engage one of the first 174 and second surrounding grooves 178 on the hollow body 14.

A mounting post 226 is provided. The post 226 has an upper end 230, a lower end 234 and is fixedly mounted at its lower end 234 to the outer surface 126 of the needle shield 122 adjacent its first end 130. The post 226 is fixedly attached at its upper end 230 to the lower surface 194 of the engaging finger 182 at the pivot point 206 such that the resilient material 186 of the engaging finger 182 will bias the securing tooth 210 downward to removably engage one of the first 174 and second surrounding grooves 178. When pressure is applied to the upper surface 190 of the engaging finger 182 adjacent its activating end 198 the securing tooth 210 will pivot upwardly away from one of the first 174 and second securing grooves 178, permitting the needle shield 122 to move slidably from the first position 142 to the second position 146. When the securing tooth 210 is positioned over one of the first 174 and second securing grooves 178 and pressure is relieved from the upper surface 190 of the engaging finger 182 the securing tooth 210 will engage one of the grooves, preventing further movement of the needle shield 122.

(2) In yet another variant, as shown in FIG. 3, the means 236 for moving the needle shield 122 from the first position 142 to the second position 146 using a single hand further comprises an indentation 238 located on the outer surface 126 of the needle shield 122 adjacent its first end 130 and is sized and shaped to engage a finger pad (not shown) of a user.

(3) In still another variant of the invention, as shown in FIG. 4, the needle shield 122 is formed of a resilient material 254 and the means 258 for containing any fluid leaking from the second end 90 of the needle 82 within the needle shield 122 when the shield 122 is secured to the hollow body 14 in the second position 146 includes a flattened closure means 262 formed at the second end 134 of the needle shield 122. The closure means 262 has a pair of mating lips 266 at the second end 134 permitting the hollow needle 82 and the second end 70 and center section 66 of the outlet portion 58 to pass between them when the needle shield 122 is in the first position 142. The lips 266 are capable of sealing the second end 134 of the needle shield 122 when the shield 122 is in the second position 146 with the hollow needle 82 and outlet portion 58 withdrawn within the shield 122.

(4) In a final variant, as shown in FIG. 5, the needle shield 122 is formed of a resilient material 254 and the means 270 for containing any fluid leaking from the second end 90 of the needle 82 within the needle shield 122 when the shield 122 is secured to the hollow body 14 in the second position 146 includes a flattened closure means 264 formed at the second end 134 of the needle shield 122. The closure means 264 has a pair of mating lips 268 at the second end 134 permitting the hollow needle 82 to pass between them when the needle shield 122 is in the first position 142. The lips 268 are capable of sealing the second end 134 of the needle shield 122 when the shield 122 is in the second position 146 with the hollow needle 82 withdrawn within the shield 122.

The safety syringe 10 has been described with reference to particular embodiments. Other modifications and enhancements can be made without departing from the spirit and scope of the claims that follow. 

1. A safety syringe, comprising: a hollow body, said body being of a first predetermined length and having an outer surface, a first end, a second end, cylindrical bore of a first predetermined diameter and means for gripping the hollow body adjacent the second end; said first end including an opening of the first predetermined diameter; said second end including a cavity extending from the cylindrical bore and terminating in an outlet portion, said outlet portion having a first end, a center section and a second end and being fixedly attached at its first end to the cavity; said outlet portion including an orifice of a second predetermined diameter, said orifice extending outwardly from said cavity; a hollow needle, said needle having a first end and a second end and being fixedly attached at its first end to the second end of the outlet portion such that fluid may travel from the cylindrical bore, through the cavity, through the outlet portion and through the needle; a plunger, said plunger having a longitudinal shaft longer than the first predetermined length, a first end and a second end, a thumb pad fixedly attached to the first end of said shaft, and a piston, said piston being formed of a resilient material, attached to the second end of said shaft, and being sized and shaped to fit sealably within the cylindrical bore of the hollow body; a needle shield, said shield having an outer surface, a first end, a second end, and being sized and shaped to fit slidably over the needle and at least a portion of the hollow body of the syringe; means for moving the needle shield from the first position to the second position using a single hand; means for containing any fluid leaking from the second end of the needle within the needle shield when the shield is secured to the hollow body in the second position; means for securing the needle shield at its first end to the hollow body in a first position, said first position permitting the second end of the needle to extend outwardly from the second end of the shield and in a second position in which the second end of the needle shield extends beyond the second end of the needle, said means comprising: a first surrounding groove, said first groove disposed upon the outer surface of the hollow body adjacent its second end; a second surrounding groove, said second groove disposed upon the outer surface of the hollow body adjacent its first end; an engaging finger, said finger being formed of resilient material and having an upper surface, a lower surface, an activating end, an attaching end and a pivot point disposed between said ends; a securing tooth, said tooth having an upper end and a lower end and being fixedly attached at its upper end to the lower surface of the engaging finger adjacent the attaching end; said securing tooth being sized, shaped and disposed to removably engage one of the first and second surrounding grooves on the hollow body; a mounting post, said post having an upper end, a lower end and being fixedly mounted at its lower end to the outer surface of the needle shield adjacent its first end; said post being fixedly attached at its upper end to the lower surface of the engaging finger at the pivot point such that the resilient material of the engagement finger will bias the securing tooth downwardly to removably engage one of the first and second surrounding grooves; and whereby, when pressure is applied to the upper surface of the engaging finger adjacent its activating end the securing tooth will pivot upwardly away from one of the first and second securing grooves, thereby permitting the needle shield to move slidably from the first position to the second position and when the securing tooth is positioned over one of the first and second securing grooves and pressure is relieved from the upper surface of the engaging finger the securing tooth will engage one of said grooves, thereby preventing further movement of the needle shield.
 2. The safety syringe as described in claim 1, wherein the means for moving the needle shield from the first position to the second position using a single hand further comprises an indentation, said indentation being disposed upon the outer surface of the needle shield adjacent its first end and being sized and shaped to engage a finger pad of a user.
 3. The safety syringe as described in claim 1, wherein the needle shield is formed of a resilient material and the means for containing any fluid leaking from the second end of the needle within the needle shield when the shield is secured to the hollow body in the second position further comprises: a flattened closure means formed at the second end of the needle shield, said closure means having a pair of mating lips at said second end, said lips permitting the hollow needle and the second end and center section of the outlet portion to pass there between when the needle shield is in the first position; and said lips being capable of sealing the second end of the needle shield when the shield is in the second position with the hollow needle and outlet portion withdrawn within the shield.
 4. The safety syringe as described in claim 1, wherein the needle shield is formed of a resilient material and the means for containing any fluid leaking from the second end of the needle within the needle shield when the shield is secured to the hollow body in the second position further comprises: a flattened closure means formed at the second end of the needle shield, said closure means having a pair of mating lips at said second end, said lips permitting the hollow needle to pass there between when the needle shield is in the first position; and said lips being capable of sealing the second end of the needle shield when the shield is in the second position with the hollow needle withdrawn within the shield. 